potter



E. M. POTTER.

Draft Equalizer.

No. 73,197. Patented Jan. 7, 1868.

J ,g I H nauk" Lg, v

fffi W IIIIII v Wtnesses: Inventor:

i ntrh istne latnt Qffif,

IMPROVEMEN T IN GLBVIS.

-.ohm

ttt tizztnle referrth tt in these Estars ntentmih making ,nurt tt the szlmt.

TO ALL WHGM IT MAY CON CERN:

Be it known that I, E.v M. POTTER, of Kalamazoo,in the county of Kalamazoo, and State of Michigan, have invented a new and improved Three-Horse Clevis; and`I do hereby deolare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being h'ad to the accompanying drawings, forming a. part of this'specification, in which- I Figure 1 is a side view of my i'mproved'clevis Figure 2 is a plan view of the same, with the whiflle-trees shown attached.

Similar letters of reference ndioate'corresponding parts.

This'invention relates to a clevis for the purpose of working more advantageously three horses abreast, When ploughing or performing equivalent work. It consists of two grooved pulleys cast in one piece, and of different diameters, and on which pulleys the whiflie-tree chains work'iu contrary directions, whereby a compensating action is instituted for the'purpose of obviating certain disadvantages which have heretofore attended the working of three horses abreast, as will be hereinaftermore fully set forth.

In the draw'ngs, A and A' are 'the pnlleys, of cast or malleable iron, working on a bolt E, which letter passes through the guard B and clevis O, as shown, and is secured in place by a nut and head, in the usual way. The guard B is not shown in fig. 2, for the purpose of giving a better view of the other parts. The object of this guard is to prevent the chains D and D' from getting oif the pulleys.

This clevis is attached to the plough in the usual manner, and to the chains are attached the whifile-trees, in the manner shown. The chain D' is for sustainng the draught of the two outside horses, and the diameter of its pulley is equal to one-half the diameter of the' pulley A, on which is attached the chain` sustaining the draught of the middle horse. The two whiflie-trees S' are attachecl to a double-tree W, and is long enough to allow space for the middle horse, as shown. The chaius pass more than half around tlfe pulleys, and are firmly secured in the grooves of the same by screws m and m', or other suitable means; By means ofthese pulleys, of different diame-ters, there is an equilibrium established between the two outside horses` and 'the middle horse, so that the excess of the working energy of the middle horse, or of the two outside horses, or of either one of the outside horses, is distri-buted upon the others, which are'thus made to sustain their proportionate draughtstrain bytheturning of the pulleys, and consequent partial winding and unwinding of the chains, accordingI to the excess of draught-force 'on either chain.

When horses would not work together evenly, as ordinarily attached to a plough, this clevis provides a compensating action, which accomplishes the equality of drauight dsired. `Should any one of the horses slip or stumble, the tension upon the slipping horse is maintained, and the disturbance of the plough thcreby prevented.

I am aware thatna Vertical lever, having arms of different leng'ths, has been employed for accomplishing a' somewhat similar result, (see patent granted to Messrs. Austin [tt Co.) This device succeeds only where the. horses draw evenly, for the vibration of the lever in practice permits but a' short und nadequate distance of compeusatingimotion to the chain, and, at the extent of its vibration, is 'stopped suddenly, thereby occasioning ajar o r strainupon the horses, Again, the departui'e of the levenfrom a. vertiool'position, maintains the relative difference of leverage throughout the extent ofits vibration, so that it requires as much force to beexerted' to bring the level' to its vertical position, and thereby restore the chai'nand whifile-trecs to their proper positions when the outside horses or the middle horse has drawn ahead or fallen back to the extent' of the vibration of the lever. These disadvautages, which attend the use of the lever-device, are obviated by my improvement, for, in the first case, the pulleys will, by revolving, permitthe maximum extension of either chain, and, in the second case, as the unwinding chain brings its point of attachment, 'm or m', to 'coinoide with'its line-of draught and the centre of the bolt, thus destroying the leverage of the extended, chain, and allowing the horse or horses attached to the shortened or wound ohain to regain their proper position with less cifort. This'last-desci'ibed' feature is one that has an important relation to the perfect Working of the team; A

It is well known that in ploughing, the shape of the mould-board often crcates a tendency in the ploug'h to bear too much to land, as it is termed, thatis, to actuatethe'plough to cntdeper into the unplon'ghed poi'tion of the soil, thereby creating side-draught,` and cnusing more .orpless difliculty for the ploughma'n, all of which is objectionable, This disadvantage is obviated by my improvements, for the small .pulley A' can be placed so as to come upon'the unploughefside, by simply ettaching the cievis tovtheipiough, with reference to the ma-nner in which the field is to be plougher'l. The line of draug'ht upon the ;small puiley is then brought to the right or left of the eentreiline of the plough, thereby compensating for the action of the mouid-boers, before mentioned, and causing thepiough to run evenly. It is cheap and durahle, and, suppiies akw ant long feit.

Having thus (iescribed my invention, what I eleiin as'new, and esire tos'ecure by Letters Patent, is-

The empioyment of the two pulleys A and A', substantiaiiy as shown and describe, in eombinetion with the ropes or chains D and D', and the oievis-iron O, or other equivaient device for the Purpose of working three horse abreast in ploughing or other equivient operation, 811 as set forth. v

The above specifioati'on of my inveution signed by me, this 9th day of November, 1867.

E. M. POTTER.

Witnesses:

W. W. PGK, A. D. RoBmsoN. 

